Overview
This lecture reviewed the structure of the solar system, focused on Earth's lithosphere layers, and compared the characteristics of continental and oceanic crust.
The Solar System and Earth's Place
- The Sun is at the center of the solar system, with eight planets revolving around it.
- Earth is the only known habitable planet in the solar system.
Layers of Planet Earth
- Earth has three layers: atmosphere (gas), hydrosphere (liquid), and lithosphere (solid).
- The lithosphere comprises four main layers: crust, mantle, outer core, and inner core.
Characteristics of Lithosphere Layers
- Crust: Only habitable layer, contains natural resources, thinnest, lightest, coldest, and topmost.
- Mantle: Magma reservoir, thickest layer, found below the crust.
- Outer Core: Liquid ball of metals, source of Earth's magnetic field, heavier than mantle, hotter than mantle.
- Inner Core: Solid ball of metals, center of gravity, heaviest, hottest, and deepest layer.
Arranging Lithosphere Layers
- By depth (top to bottom): crust, mantle, outer core, inner core.
- By thickness (thin to thick): crust, inner core, outer core, mantle.
- By density (light to heavy): crust, mantle, outer core, inner core.
- By temperature (cold to hot): crust, mantle, outer core, inner core.
Magma vs. Lava
- Magma: Molten rock found inside the mantle or below the crust.
- Lava: Magma that has erupted and reached the Earth's surface.
Earth's Surface: Continents and Oceans
- Earth has seven continents: Asia, Africa, North America, South America, Antarctica, Europe, Australia.
- Earth has five major oceans: Pacific, Atlantic, Indian, Antarctic, Arctic.
Types of Earth's Crust
- Continental Crust: Supports continents, mostly granite, thicker, lighter, and elevated.
- Oceanic Crust: Supports oceans, mostly basalt, thinner, heavier, and located below sea level.
Key Terms & Definitions
- Lithosphere — Solid layer of the Earth, consisting of crust, mantle, outer core, and inner core.
- Crust — Earth's outermost solid layer, supports life.
- Mantle — The thick, magma-filled layer beneath the crust.
- Outer Core — The Earth's liquid metal layer, generates magnetic field.
- Inner Core — Solid metal center of the Earth; hottest and densest layer.
- Magma — Molten rock beneath Earth's surface.
- Lava — Molten rock erupted onto Earth’s surface.
- Continental Crust — Thick, granite-rich, lighter crust under continents.
- Oceanic Crust — Thin, basalt-rich, heavier crust under oceans.
Action Items / Next Steps
- Prepare for the first performance task tomorrow.